1. Field of the Invention
The present invention relates to a photoelectric conversion element having an indium oxide-containing transparent conductive layer prepared by a coating and thermal decomposition method.
2. Prior Art
Thin metal films such as gold, silver, aluminum, and metal oxides such as zinc oxide and ITO (Indium-Tin-Oxide) are generally known as a transparent conductive layer for use in solar cells. Sputtering methods and vapor deposition methods are well known as methods for preparing the ITO. (Electroceramics, '85. May, p. 23 (1985)). A method for preparing an indium oxide coating film by a coating and thermal decomposition method is described in Japanese Patent Publication No. Sho 54-28396.
However, the thin metal films such as gold, silver, and aluminum had low light transmission and the zinc oxide film having a high light transmission in the spectral range from the visible to the infrared had a low conductivity. In addition, the ITO transparent conductive layer prepared by a sputtering method or vapor deposition method had a high conductivity but the preparation process thereof was complicated and the layer had no infrared transmission. Thus, there was no transparent conductive material for use in solar cells having a high conductivity and a high light transmission property in the range from visible to infrared. Further, there was no disclosure of a combination of an indium oxide film prepared by a coating and thermal decomposition method having infrared transmission and a high conductivity, and a photoconductive material having a photosensitivity to infrared rays.